Two-Dimensional Subsonic Wind Tunnel Evaluation of a 20-Percent-Thick Circulation Control Airfoil.

摘要

A circulation control uncambered elliptic airfoil section with a thickness-to-chord ratio of 0.20was tested subsonically to determine its aerodynamic characteristics. Lift coefficients up to 5were produced at momentum coefficients,of 0.24. The initially high unblown drag coefficients,characteristic of bluff trailing edge airfoils,were greatly reduced at low values of momentum coefficient. It was therefore possible to produce equivalent lift-to-drag ratios in excess of 30when Cl = 1.0. The ability to produce high lift coefficients essentially independent of angle of attack is indicated by the results of this investigation. (Author)